function circleArea(radius){
    return Math.PI*radius
}
function circleArea(radius){
    return 2*Math.PI*radius
}
const radius =3.14
const area =circleArea(radius)
const perimeter = circlePermeter(radius)
console.log(`圆的面积为:${area}`)
console.log(`圆的周长为:${perimeter}`)